CASE STUDY

Open networking standards and the road to agility, part 1: OpenDaylight

Open networking standards and the road to agility, part 1: OpenDaylight

Posted by Hans Ashlock January 5, 2015

Open source projects and protocols hold great potential for networking. Already, initiatives such as OpenStack and OpenDaylight have attracted the attention of many major vendors, with Intel, for example, recently joining OpenDaylight as a platinum member. Moreover, the industry-wide momentum has been sufficient to spur telecoms such as AT&T to create their own open source efforts like the Open Networking Lab.

Beginning with this entry, we'll examine various open networking standards and how they are influencing network engineering as well as telecom and IT strategy. One could generally say that in the wake of open source development, teams have become more concerned with APIs, DevOps automation and the need for agility, but each standard brings something new to the table. We'll start with OpenDaylight.

OpenDaylight: Open SDN is gaining traction
The Linux Foundation manages OpenDaylight, which is fundamentally an effort to accelerate the development of software-defined networking and network functions virtualization. Though not even two years old, OpenDaylight is already one of the largest open source projects in the world, with 266 developers having contributed in the past 12 months and the project as a whole having surpassed 1 million lines of code in early 2014.

What does OpenDaylight specifically address? It is perhaps best understood as enabling a variety of technologies implemented in multiple layers across a network:

The data plane layer consists of the physical and virtual devices in the network.

Above that, in the center, is the OpenDaylight controller platform with northbound and southbound APIs exposed for connecting to the application layer and underlying data plane layer hardware, respectively.

At the top is orchestration and other services for network applications. This layer contains the SDN interface and hooks for OpenStack Neutron, for example.

The overarching principle of OpenDaylight is compatibility with any type of switching hardware via a controller that is implemented completely within software. In fact, the controller platform runs on its own Java Virtual Machine and supports the Open Service Gateway Initiative. OpenDaylight interacts with many APIs and standards-based protocols like OpenFlow to facilitate a wide range of SDN use cases.

Vendors and the future of OpenDaylight
Plenty of vendors are on board with OpenDaylight, to the extent that its detractors have argued that the project, despite its open source designation, may end up actually preserving the position of networking incumbents. Cisco and IBM founded OpenDaylight and were followed as members by Brocade, Juniper, Microsoft, Intel and others.

With OpenDaylight in particular, the contributions of Cisco have often been scrutinized due to Cisco's unique take on SDN and what type of controller should be used. Network World's Jim Duffy referred to Cisco OpFlex as an "OpenFlow killer" last spring, which may be an exaggeration, but it's clear that Cisco has something other than OpenFlow in mind for the future of OpenDaylight's core.

OpFlex could be a key part of the Lithium release that will succeed OpenDaylight Helium. However, Guru Parulkar, director of the Open Networking Lab, cited OpFlex's exposure of device specifics to applications as a needless complication and one of the reasons for creating an alternative to OpenDaylight.

Ultimately, it's a hard balance for vendors to strike between innovating in their own product and service lines and participating in the open source community. Projects like OpenDaylight demonstrate both the promise of open source software in enabling SDN orchestration and the risks of new developments being driven by incumbents. A middle path is needed.

"The vendor's role in open-source networking projects should be a symbiotic one with other members of the community," wrote Mike Cohen for TechCrunch. "This includes contributing to open-source efforts for the good of the community while continuing to innovate and build differentiated products that better meet user needs. Vendors should also contribute some of those innovations back to the community to help promote new standards that will help the market continue to grow."

The takeaway: OpenDaylight, initiated by Cisco and IBM in 2013 and now hosted by the Linux Foundation, is one of the most prominent open source software movements at the moment. It defines a flexible controller and set of APIs for different types of infrastructure, as a way of enabling SDN and NFV. The shape that vendor contributions to and relationships with OpenDaylight take will be critical to its future as an inclusive effort at improving network automation and orchestration.